Entity Framework and Nested Lambda Expressions
I've just started using Lambda expressions, and really like the shortcut. I also like the fact that I have scope within the lambda of the encompassing method. One thing I am having trouble with is nesting lambdas. Here is what I am trying to do:
public void DoSomeWork()
{
MyContext context = new MyDomainContext();
context.GetDocumentTypeCount(ci.CustomerId, io =>
{
if (io.HasError)
{
// Handle error
}
// Do some work here
// ...
// make DB call to get data
EntityQuery<AppliedGlobalFilter> query =
from a in context.GetAppliedGlobalFiltersQuery()
where a.CustomerId == ci.CustomerId && a.FilterId == 1
select a;
context.Load<AppliedGlobalFilter>(query, lo =>
{
if (lo.HasEr开发者_开发百科ror)
{
}
**// Do more work in this nested lambda.
// Get compile time error here**
}
}, null);
}, null);
}
The second lambda is where I get the following compile time error:
Cannot convert Lambda expression to type 'System.ServiceModel.DomainService.Client.LoadBehavior' because it is not a delegate type
The compiler is choosing the wrong overload for the Load method even though I am using the same override I did in the previous Lambda.
Is this because I am trying to nest? Or do I have something else wrong?
Thanks,
-Scott
Found the problem as described in my comment above. I'll head back to work now - red face and all....
I realize this is not the answer you want, but I suggest caution about lengthy and/or nested lambdas. They work, but they often make code harder to read / maintain by other developers. I try to limit my lambdas in length to three statements, with no nesting.
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